1. Field of the invention
The invention relates to apparatus for simultaneously sending a telephone call over a subscriber telephone line from a PSTN compatible telephone terminal on a subscriber site, and IP packets from a first computer, to apparatus for simultaneously receiving a telephone call to a PSTN compatible telephone terminal on the subscriber site, and IP packets directed to a first computer, both sent over a subscriber telephone line, to methods of using such apparatus, and to software for carrying out such methods.
2. Background Art
The most common way of accessing on-line services using the Internet is via a modem link over a dial-up PSTN connection. However, this may tie up the user{acute over (1)}s telephone line for long periods. Incoming and outgoing voice telephone calls cannot be made or completed. Similarly, when the telephone line is being used for a voice telephone call, the Internet cannot be accessed.
One known solution to this problem is to have a second line installed. However, additional expense is involved and the second line may be accessible from only one room in the house or small office, unless major rewiring work is carried out to make both lines accessible in many rooms.
An alternative solution is called the Internet Phonejack. This is a telephony expansion card which can be plugged into a PC, and enables Internet telephony applications such as Microsoft Netmeeting to interface with conventional telephone terminals. The card emulates an ordinary subscriber telephone line, and thus enables such telephone terminals to be used for voice calls at the same time as the computer user is accessing the Internet. The analog voice signals are converted into Internet Protocol (IP) packets which can be interleaved with IP packets used by the computer for accessing other services over the Internet simultaneously.
Another known system is called the Phone Doubler, produced by Ericsson. FIG. 1 illustrates this known arrangement in schematic form. A user{acute over (1)}s PC (Personal Computer) 20 is connected to a subscriber telephone line using a modem 40. Phone doubler client software 30 runs on the PC. A headset 10 with microphone and earphone is connected to the PC.
Away from the subscriber{acute over (1)}s location, the rest of the PSTN/ISDN 50 links other elements of the arrangement. A VOIP (Voice over Internet Protocol) gateway 70 is connected to the PSTN and to an Internet access server 80. The VOIP gateway and the Internet access server may be co-located and connected by a local area network such as an ethernet link. The Internet access server is linked to the rest of the Internet 90, and also to the PSTN.
In operation, when an incoming call from a remote telephone 60 is routed by the PSTN to the subscriber with the PC 20, if the subscriber is already connected to the Internet over his subscriber line, the local central office (not shown) in the PSTN will be arranged to divert the call to the phone doubler VOIP gateway, assuming the subscriber has previously subscribed to this phone doubler service. The VOIP gateway will receive the call and will look up the IP address of the subscriber, based on the telephone number of the subscriber which has been dialed from the remote telephone 60. The gateway determines if the user already has an IP session with the Internet access server, and if so, communicates with the phone doubler client software 30 to offer the user the option of taking the call.
If the user accepts the call, the gateway converts the incoming voice signals into UDP (User Datagram Protocol) format, which uses IP for transmission. The phone doubler client 30 receives the IP packets, assembles the UDP datagrams, converts them back into the analog voice signals, which are fed to the headset 10. Voice signals from the subscriber can be transmitted in a corresponding way back to the remote telephone 60. This achieves a virtual second line for a user, to enable simultaneous voice and on-line access over a single subscriber line.
It is also known to provide systems to enable multiple computers to access the Internet over a single subscriber line simultaneously. The multiple computers may be connected over a local area network (LAN), and an Internet LAN bridge can be used to enable multiple LAN users to share a single dial-up Internet connection at the same time.
Another known system, called HomeRun has been proposed by TUT Systems, and uses existing telephone wiring in the home or office to create an ethernet LAN. It has been proposed to use this to provide Internet access throughout the home or office by linking all the computers to a modem which can maintain a single dial up connection to an ISP (Internet Service Provider), by creating a LAN over the existing telephone wiring. The networking signals and standard telephone service can coexist on the same wires at the same time, using frequency division multiplexing. Ordinary telephones can be used without alteration. PCs can be plugged in to the telephone sockets using interface cards which support a standard RJ11 phone jack, and include an ethernet interface.
It is also known to modify the equipment at each end of the subscriber telephone line to provide a higher bandwidth service over the subscriber line, e.g. 128 kbps for ISDN (Integrated Services Digital Network) or higher for xDSL (High Speed Digital Subscriber Line) type systems. For an ISDN line, two channels are multiplexed over a single physical path. The interfaces at each end may be arranged so that voice calls use one of the two channels, while the other may be used to carry data, to enable online services to be accessed simultaneously. xDSL encompasses a range of different types of digital subscriber line systems including ADSL (Asynchronous Digital Subscriber Line), requiring specialized equipment at both ends of the subscriber line.
In this document, PSTN compatible telephone terminals shall be defined as excluding ISDN or ADSL compatibility. PSTN compatible is intended to encompass compatibility with a basic public telephone service interface. Such terminals use a conventional tip and ring analog interface, for use with one 64 kbit channel in the PSTN network. They may have a wired handset or a cordless handset, or a speaker phone, for example.
The term IP is intended to encompass any version of the Internet Protocol and any other protocols which may be used for carrying Internet traffic with ISO layer three functions.
It is an object of the invention to provide improved methods and apparatus.
According to a first aspect of the invention there is provided apparatus for use with a subscriber telephone line connecting a subscriber site and a telephone network, for simultaneously sending a telephone call from a PSTN compatible telephone terminal on the subscriber site, and IP packets from a first computer, over the subscriber telephone line, the apparatus comprising:
a converter having a PSTN compatible telephone line interface for coupling to the PSTN compatible telephone terminal, the converter being for converting signals from the PSTN compatible telephone terminal into IP packets representing the telephone call; and
a multiplexer coupled to the converter, and having a computer interface for coupling to the first computer, and a subscriber line interface for coupling to the subscriber telephone line, the multiplexer being arranged for sending simultaneously the IP packets representing the telephone call and those from the computer, along the subscriber telephone line;
the apparatus being arranged to handle telephone calls without conversion to IP packets, between the telephone terminal and the subscriber telephone line when the subscriber telephone line is not used for carrying IP packets.
One of the problems of the prior art, discovered and addressed by this aspect of the invention is the ability to provide, using one subscriber line, e.g. a conventional POTS (Plain Old Telephone Service) line, that all phones in a household remain operational (i.e., they can be used to make and receive calls), while one or more PCs are concurrently accessing online services, without needing a second line, or special equipment to increase the bandwidth transmissible over the line by a factor of two or more.
One advantage of providing the capability of handling phone calls from the PSTN compatible telephone terminal on the subscriber line either over a telephone interface, or in the form of IP packets is that it enables a single subscriber line to be used for both purposes. This cannot be achieved with traditional telephones which can always only use the telephone interface, nor with the Internet phone jack and Phone doubler products which can always only carry calls in the form of IP packets.
Another advantage arises from the converter having a PSTN compatible interface. One consequence of this is that existing telephones, extension telephones and telephone cabling in a house or office can continue to be used even when the subscriber telephone line is carrying IP packets. This previously would have required a second line. In the above mentioned Internet phone jack and Phone Doubler products, telephony is limited to a headset and microphone belonging to the computer, or to a telephone terminal belonging to the computer.
With respect to the above mentioned known ISDN or ADSL systems, such systems have no converter, but require expensive dedicated linecards and other expensive equipment at the central office and the Internet service provider to provide a bandwidth of 128 Kbps or higher. The converter enables telephony and IP services to be carried simultaneously at much lower cost, over a conventional subscriber telephone line. The apparatus does not require additional equipment on the subscriber telephone line to provide a high bandwidth service. It only requires the bandwidth that a conventional subscriber telephone line supports for conventional dialed telephone calls.
Preferably the apparatus further comprises a bridge for selectively coupling the subscriber telephone line to an internal telephone line to which the telephone terminal is attached.
This can enable an advantage to be achieved in that telephone calls can be routed directly without using the converter when the computer is not using the subscriber line, and in that telephone calls can be converted into IP packets and be routed in an IP session when the computer is using the subscriber telephone line for an IP session. Further, this can also enable a second advantage in that when the internal cabling is not coupled to the subscriber telephone line, the internal cabling can be used for purposes such as telephone calls between terminals within the customer site, without interfering with signals on the subscriber telephone line.
Preferably, the telephone terminal is coupled to the apparatus via an internal telephone line, the apparatus further comprising a telephone data interface coupled to the multiplexer and arranged for coupling to the internal telephone line, for receiving data from a further computer coupled to the internal telephone line, and distinguishing this data from analog signals from the telephone terminals, the multiplexer being arranged to send the data from the further computer along the subscriber telephone line.
One advantage which can arise here is that the further computer can make use of existing internal telephone cabling in a house or office to access online services over the subscriber line. Furthermore, it may be possible to do so simultaneously with the first computer using the subscriber line, or with a telephone call taking place, or even simultaneously with both of these possibilities. The above mentioned Homerun product can be used to enable multiple computers to concurrently access online services over a conventional subscriber telephone line and existing internal cabling. However, in such an arrangement the existing telephone terminals connected to the internal cabling cannot be used to send or receive calls while a computer is online.
Preferably, the telephone terminal is coupled to the apparatus via an internal telephone line, the apparatus further comprising a telephone data interface coupled to the multiplexer and for coupling to the computer interface, for receiving data from a further computer coupled to the internal telephone line, the multiplexer being arranged to send the data from the further computer to the first computer.
This enables multiple computers to communicate amongst themselves using existing telephony cabling. This enables many of the advantages of a local area network to be achieved using existing cabling. Furthermore the combination of this local area network capability with the capability of the first computer to access online services while maintaining telephony, can make it possible for the further computer to access online services via the first computer. Alternatively, or concurrently, telephone terminals can make and receive calls.
Preferably the telephone line interface and the telephone data interface are arranged to communicate over the internal telephone line simultaneously.
The combination of this local area network capability with the capability of the apparatus to access online services while maintaining telephony, can make it possible for any or many computers to access online services via the apparatus while concurrently allowing telephone terminals anywhere on the internal telephone line to make and receive calls. In the above mentioned Homerun product, a computer can communicate with a further computer while a call is being made from a conventional telephone terminal. However, in such an arrangement, the computers may not access online services at the same time as the call is being made from the conventional telephone terminal.
Preferably the telephone line interface further comprises an internal line monitor for determining the state of telephony activity from the telephone terminal, the apparatus being arranged to control a telephone call in response to the determination.
An advantage of this is that it enables the call to be controlled as desired by the end user.
Preferably the apparatus further comprises a subscriber line monitor for determining the state of the subscriber telephone line the apparatus being arranged to control a telephone call in response to the determination.
This can help in deciding if the call can be established in conventional non-IP form.
Preferably the apparatus further comprises an IP session monitor for determining when there is an IP session already existing, the apparatus being arranged to control a telephone call in response to this determination.
This can help decide whether the call can be established using an existing IP session.
Preferably the apparatus further comprises an internal line monitor for determining the state of telephony activity from the telephone terminal, and a subscriber line monitor for determining the state of the subscriber telephone line, the apparatus being arranged to control the call additionally on the basis of the outputs of the internal line monitor and the subscriber line monitor.
In combination the capability to monitor telephony activity from the telephone terminal and the capability to monitor the state of the subscriber telephone line, provide an advantage for example in enabling voice over IP resources to be used to establish a call when the subscriber telephone line is being used already to access an online service, or according to other criteria, e.g. if it is more cost effective. A second advantage would be to facilitate a decision to establish the call as a conventional analog telephony call for example when an IP session is not established and the subscriber telephone line is idle.
Preferably the telephone line interface is arranged to determine what number has been dialed, and establish the call as a VoIP call, or establish the call as a conventional telephone call, on the basis of the number dialed.
An advantage is that the decision of whether to route the call using VoIP or non VoIP can be made automatically for example when it is more cost effective, or when instructed by the subscriber.
Preferably the apparatus further comprises an internal line monitor, for determining the state of telephony activity from the telephone terminal, the apparatus being arranged to send a busy indication in response to an incoming call for the telephone terminal, if an IP session is established and if the internal line monitor determines that the telephone terminal is busy.
Preferably the apparatus is arranged to prompt a caller of an incoming call to indicate a party that he intends to reach, and the telephone interface is arranged to process the call on the basis of the party indicated by the caller.
Preferably the telephone line interface is arranged to output an alert specific to the party indicated by the caller.
Preferably the multiplexer further comprises a second subscriber line interface for coupling to a second subscriber line.
This can enhance the apparatus by allowing for example a non VoIP call on one line at the same time as one or more IP sessions are being handled over the other line.
Preferably the multiplexer further comprises a second subscriber line interface for handling a second connection over the subscriber telephone line, for use with a high bandwidth coupler for multiplexing the second connection over the subscriber telephone line.
This can enhance the apparatus by allowing for example a non VoIP call on the subscriber line at the same time as one or more IP sessions are being handled in the second connection over the subscriber telephone line.
According to a further aspect of the invention, there is provided apparatus for use with a subscriber telephone line connecting a subscriber site and a telephone network, for simultaneously sending a telephone call from a PSTN compatible telephone terminal on the subscriber site coupled to an internal telephone line, and data from a computer coupled to the internal telephone line, over the subscriber telephone line, the apparatus comprising:
a converter having a PSTN compatible telephone line interface for coupling to the PSTN compatible telephone terminal, the converter being for converting signals from the PSTN compatible telephone terminal into IP packets representing the telephone call;
a telephone data interface for coupling to the internal telephone line for receiving the data from the computer over the internal telephone line, the telephone line interface and the telephone data interface being arranged to communicate over the internal telephone line simultaneously; and
a multiplexer coupled to the converter, and coupled to the telephone data interface, and having a subscriber line interface for coupling to the subscriber telephone line, the multiplexer being arranged for sending simultaneously the telephone call and the data from the computer, along the subscriber telephone line in the form of IP packets.
The above mentioned problem of the prior art, is also addressed by this aspect of the invention. All phones in a household remain operational (i.e., they can be used to make and receive calls), while one or more PCs are concurrently accessing online services, without needing a second line, or special equipment to increase the bandwidth transmissible over the line by a factor of two or more. Compared to the first aspect, at least one of the PCs makes use of the internal telephone line to reach the subscriber line, but the direct computer connection with the apparatus avoiding using the internal telephone line, is optional.
Preferably the apparatus further comprises a bridge for selectively coupling the subscriber telephone line to the internal telephone line.
Preferably the telephone data interface comprises a local area network interface for coupling more than one computer to the apparatus.
According to a further aspect of the invention, there is provided apparatus for use with a subscriber telephone line connecting a subscriber site and a telephone network, for simultaneously receiving a telephone call to a PSTN compatible telephone terminal on the subscriber site, and IP packets directed to a first computer, both sent over the subscriber telephone line, the apparatus comprising:
a converter having a PSTN compatible telephone line interface for coupling to the PSTN compatible telephone terminal, the converter being for converting from IP packets representing the telephone call into signals for the PSTN compatible telephone terminal; and
a demultiplexer coupled to the converter, and having a computer interface for coupling to the first computer, and a subscriber line interface for coupling to the subscriber telephone line, the demultiplexer being arranged for receiving simultaneously the IP packets representing the telephone call and those for the computer, over the subscriber telephone line;
the apparatus being arranged to handle telephone calls without conversion to IP packets, between the telephone terminal and the subscriber telephone line when the subscriber telephone line is not used for carrying IP packets.
According to a further aspect of the invention, there is provided apparatus for use with a subscriber telephone line connecting a subscriber site and a telephone network, for simultaneously receiving over the subscriber telephone line from the subscriber site a telephone call from a PSTN compatible telephone terminal coupled to an internal telephone line and data for a computer coupled to the internal telephone line, the apparatus comprising:
a converter having a PSTN compatible telephone line interface for coupling to the PSTN compatible telephone terminal, the converter being for converting IP packets representing the telephone call into signals for the PSTN compatible telephone terminal; a telephone data interface for coupling to the internal telephone line for receiving the data from the computer over the internal telephone line; and
a demultiplexer coupled to the converter, and to the telephone data interface, and a subscriber line interface for coupling to the subscriber telephone line, the demultiplexer being arranged for receiving simultaneously the telephone call and the data for the computer, over the subscriber telephone line in the form of IP packets.
According to a further aspect of the invention, there is provided a method of simultaneously sending a telephone call from a PSTN compatible telephone terminal on a subscriber site and IP packets from a first computer, over a subscriber telephone line, the method comprising the steps of:
converting signals from the PSTN compatible telephone terminal into IP packets representing the telephone call;
using a multiplexer coupled to the converter, and having a computer interface for coupling to the first computer, and a subscriber line interface for coupling to the subscriber telephone line, to send simultaneously the IP packets representing the telephone call and those from the computer, along the subscriber telephone line; and handling telephone calls without conversion to IP packets, between the telephone terminal and the subscriber telephone line when the subscriber telephone line is not used for carrying IP packets.
According to a further aspect of the invention, there is provided a method of simultaneously sending a telephone call from a PSTN compatible telephone terminal on a subscriber site coupled to an internal telephone line, and data from a computer coupled to the internal telephone line, over a subscriber telephone line, the method comprising the steps of:
converting signals from the PSTN compatible telephone terminal into IP packets representing the telephone call; using a telephone data interface coupled to the internal telephone line for receiving the data from the computer over the internal telephone line; and
using a multiplexer coupled to the converter, and to the telephone data interface, and having a subscriber line interface for coupling to the subscriber telephone line, to send simultaneously the telephone call and the data from the computer, along the subscriber telephone line in the form of IP packets.
Another aspect of the invention provides software stored on a computer readable medium for carrying out the above methods.
Any of the preferred features may be combined, and combined with any aspect of the invention, as would be apparent to a person skilled in the art. Other advantages will be apparent to a person skilled in the art, particularly in relation to prior art other than that mentioned above.
To show, by way of example, how to put the invention into practice, embodiments will now be described in more detail, with reference to the accompanying drawings.